Documentation of decorators should should show where to look for arguments' reference

[MrMino]

I've just started exploring click, and wholeheartedly love it. Thanks!

One thing that made the experience a bit frustrating was the API reference. Currently, in some places, it omits descriptions of the arguments of some of the decorators. For example, with click.argument, it just says the type is Any without telling where to look for the actual description:

I guess it's because the underlying argument class is customizable, but for the default usecase it would be nice to have a reference to the default.

Clicking on the reference to click.Argument doesn't reveal much either:

It would be nice if the description of attrs pointed to their actual reference: click.Parameter in case of argument and option decorators.

There's already a precedent for this in the docs - click.Group: